I'm looking to put my 2012 back to stock to trade it in if I can't find a private buyer in a few weeks. I no longer have the stock exhaust, still have the down pipe though. So I need an exhaust to make this happen.

I would be surprised if that actually even fit what its listed to fit on. That header is junk and destin to fail and/or have fitment issues. There are a select few things you can cheap out on and luck up with ebay specials. A header is not one of them.